{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-47185 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-47185 is a medium-severity denial of service vulnerability in Linux kernel, published on 10 Apr 2024. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2021-47185 and fix it if it is affected.\n\nWhat it is: CVE-2021-47185 is a medium-severity denial of service vulnerability in Linux kernel, published on 10 Apr 2024. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2021-47185 in the wild and no public exploit code.\n\nAffected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2021-47185/ (Markdown: https://insights.sbomify.com/CVE-2021-47185/index.md)","id":"CVE-2021-47185","markdown":"https://insights.sbomify.com/CVE-2021-47185/index.md","name":"CVE-2021-47185","record":{"aliases":["DEBIAN-CVE-2021-47185","GHSA-gvxc-64wh-vgv2","UBUNTU-CVE-2021-47185"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":true,"product_category":"Linux kernel","requires_auth":"high_privilege","summary":"A local attacker can cause a soft lockup in the Linux kernel's tty buffer handling by rapidly writing to a pty, leading to a denial of service.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":4.4,"severity":"medium","source":"cisa-adp","vector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-667","name":"Improper Locking"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntty: tty_buffer: Fix the softlockup issue in flush_to_ldisc\n\nWhen running ltp testcase(ltp/testcases/kernel/pty/pty04.c) with arm64, there is a soft lockup,\nwhich look like this one:\n\n  Workqueue: events_unbound flush_to_ldisc\n  Call trace:\n   dump_backtrace+0x0/0x1ec\n   show_stack+0x24/0x30\n   dump_stack+0xd0/0x128\n   panic+0x15c/0x374\n   watchdog_timer_fn+0x2b8/0x304\n   __run_hrtimer+0x88/0x2c0\n   __hrtimer_run_queues+0xa4/0x120\n   hrtimer_interrupt+0xfc/0x270\n   arch_timer_handler_phys+0x40/0x50\n   handle_percpu_devid_irq+0x94/0x220\n   __handle_domain_irq+0x88/0xf0\n   gic_handle_irq+0x84/0xfc\n   el1_irq+0xc8/0x180\n   slip_unesc+0x80/0x214 [slip]\n   tty_ldisc_receive_buf+0x64/0x80\n   tty_port_default_receive_buf+0x50/0x90\n   flush_to_ldisc+0xbc/0x110\n   process_one_work+0x1d4/0x4b0\n   worker_thread+0x180/0x430\n   kthread+0x11c/0x120\n\nIn the testcase pty04, The first process call the write syscall to send\ndata to the pty master. At the same time, the workqueue will do the\nflush_to_ldisc to pop data in a loop until there is no more data left.\nWhen the sender and workqueue running in different core, the sender sends\ndata fastly in full time which will result in workqueue doing work in loop\nfor a long time and occuring softlockup in flush_to_ldisc with kernel\nconfigured without preempt. So I add need_resched check and cond_resched\nin the flush_to_ldisc loop to avoid it.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"tty: tty_buffer: Fix the softlockup issue in flush_to_ldisc","id":"CVE-2021-47185","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"denial_of_service","year":"2021"},"n_packages":0,"n_references":8,"next":{"headline":"tipc: check for null after calling kmemdup","id":"CVE-2021-47186"},"packages":[],"prev":{"headline":"i40e: Fix NULL ptr dereference on VSI filter sync","id":"CVE-2021-47184"},"products":["Linux"],"published":"2024-04-10","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-05-11","vendors":["Linux"]},"summary":"A local attacker can cause a soft lockup in the Linux kernel's tty buffer handling by rapidly writing to a pty, leading to a denial of service.","url":"https://insights.sbomify.com/CVE-2021-47185/"}